Process of producing dyed cellulose ester.



BEN-NO IBORZYKOWSKI, F CHARLOZITENBUBG, GERMANY.

rnocns s or rnonuctne DYED CELLULOSE ESTER.

1,041,587; No Drawing.

To all whom it m ay concern:

Be it known that I, BENNO BoRzYKow- SKI. a subject of the Emperor of Russia, and

resident of Charlottenburg, Germany, have invented a certain new and useful Improvement in Processes of Producing Dyed Cellulose Ester, of which the following is a specification.

Several processes are already known for dyeing acetyl cellulose or for producing it in a dyed condition. For example cellulose has first. been dyed and then etherized or prepared acetyl cellulose has been dyed by using swelling means or organic solvents whichareintended to produce receptivenes's of the cellulose esters which are otherwise indifferent to dyes.

In accordanceflwith .the present process dyed cellulose esters which are exceedingly fast against light and washing are produced in a single process the dye being dissolved for example directly in the acidylizing mixture or in a portion of the acetic acid and thereafter the cellulose, hydroor oxy-cellulose (hereinafter-referred to as a cellulosic material) isbrought into this coloring solution by heating. As there are now a large number of fastdyes which resist acids. by

the use of such suitable dyes. products brightly dyed and of exceedingly fast properties are produced by this very simple process without special precautionary measures.

introducing such 'a dyed-solution of formyla a'cetylor .propionyl-cellulose, etc., into one of the usual precipitating media such as water, benzol, alcohol and so on abrightand clearly dyed product in the desired form such as yarn, film, etc., which do not bleedin the precipitating bath, do not 7 give up the dye on further treatment, and

possess the same strength as in the uncolored condition. On treatment with the usual solvents such for example as chloroform,-

acetone, dichlor'ethylene, etc., the dyed celluloseproducts pass clearly into the solution and can be further treated without alteration of the tint.

I Example: 100 parts of cleaned and dried cotton is introduced and stirred into a mixture of 450 parts of acetic acid anhydrid and Specification of Letters Patent. Application filed l l'une 11, 1912. Serial No. 702,989.

Patented Oct. 15,1912.

400 parts of acetic acid which contains 2% of concentrated sulfuric acid; at the same time a solution of a dye such for example as Bismarck brown in 100 parts of acetic acid is added and the whole mass is heated in the water bath until a clear brown solution is produced.

Instead of dissolying the dye separately itcan be added directly to the acetylizing mixture and can be stirred in. The same results are obtained when the dye is added before heating or to the-prepared acetylizing mass.

The same process is carried out with other dyes. as, for example, metanile yellow, chrysophenin G, fastscarlet colors, substantive blacks, etc. l

The solutions of' dyed acidylized cellulose thus obtained can be further treated directly. T

1. A process of producing dyed cellulose esters, said process comprising the simultaneous treatment of a cellulosic material with a suitable dye and an acidylizing agent.

2. A process of producing dyed cellulose acetate, said process comprising the simultaneous treatment of a cellulosic material with a suitable dye and an acetylizing agent.

Aprocess of producing dyed cellulose esters. said process comprising the simultaneous treatment of cellulose with a suitable dye and an acidylizing agent.

4. A process of producing dyed cellulose esters, said process comprising the simultaneous treatment of a cellulosic material with a suitable dye and a mixture of acetic acid, acetic anhydrid and sulfuric acid.

5. A process of producing dyed cellulose esters-said process comprising the simulta- I neous treatment of a cellulosicmaterial with an acid-soluble dye and an acidylizing agent.

In testimony whereof I have signed my name to this specification in the prewng of two subscribing witnesses.

, BENNO BORZYKOWSKI.

\ Witnesses: v

' CLARENCE CoRRIoAN,

Martins Hammer. 

